1. Field of the Invention
The present invention generally relates to digital image processing, and more particularly to an object-based system and method of directing visual attention by a subliminal cue.
2. Description of Related Art
Visual attention is an important characteristic of human visual system (HVS), which is a part of the central nervous system. The visual attention helps our brain to filter out excessive visual information and enables our eyes to focus on particular regions of interest.
In practice, it is necessary to direct a viewer's visual attention to a specific area, or an area of interest (AOI), in an image without letting the viewer know the intention of this action. This purpose is conventionally attained using perceivable image changes to engage viewer's awareness, for example, deliberately changing the color of a target region in an image to direct human visual attention to the target region. However, the perceivable image changes engaging viewer's awareness are not preferred for the following reasons. First the perceivable changes may lead to distractions that spoil the viewer's viewing experience. Second, the perceivable changes may cause the viewer to have a perception of the image different from the planned intention. Third, image details in the target region may be altered or lost. Moreover, the conventional method normally involves manual adjustment task and is thus not suitable for real-time applications.
For the foregoing reasons, a need has arisen to propose a novel scheme of directing viewer's visual attention in a non-intrusive and effective manner.